I lift weights "cause the chicks dig it" with the ability to draw heavy poundage a nice side effect.

However, if that's not your thing, keep doing what you're doing, and when you can do so comfortably (meaning an increase in strength) bump up the poundage and start over, and so forth, and so on...

But just remember, the ability to do so with 70# and properly warmed up is usually negated by adrenaline, sitting for hours without moving in single digit temps and the buck of a lifetime...